Commit b5f53d04 authored by Dr. David Alan Gilbert's avatar Dr. David Alan Gilbert Committed by Michael S. Tsirkin
Browse files

virtio: Use auto rcu_read macros 



Use RCU_READ_LOCK_GUARD and WITH_RCU_READ_LOCK_GUARD
to replace the manual rcu_read_(un)lock calls.

I think the only change is virtio_load which was missing unlocks
in error paths; those end up being fatal errors so it's not
that important anyway.

Signed-off-by: default avatarDr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20191028161109.60205-1-dgilbert@redhat.com>
Reviewed-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 068ddfa9

hw/virtio/virtio.c

+23 −42
Original line number Diff line number Diff line
@@ -387,7 +387,8 @@ static inline void vring_set_avail_event(VirtQueue *vq, uint16_t val) 


static void virtio_queue_split_set_notification(VirtQueue *vq, int enable)

{

    rcu_read_lock();

    RCU_READ_LOCK_GUARD();



    if (virtio_vdev_has_feature(vq->vdev, VIRTIO_RING_F_EVENT_IDX)) {

        vring_set_avail_event(vq, vring_avail_idx(vq));

    } else if (enable) {
@@ -399,7 +400,6 @@ static void virtio_queue_split_set_notification(VirtQueue *vq, int enable) 
        /* Expose avail event/used flags before caller checks the avail idx. */

        smp_mb();

    }

    rcu_read_unlock();

}



static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable)
@@ -408,7 +408,7 @@ static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) 
    VRingPackedDescEvent e;

    VRingMemoryRegionCaches *caches;



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    caches  = vring_get_region_caches(vq);

    vring_packed_event_read(vq->vdev, &caches->used, &e);
@@ -429,7 +429,6 @@ static void virtio_queue_packed_set_notification(VirtQueue *vq, int enable) 
        /* Expose avail event/used flags before caller checks the avail idx. */

        smp_mb();

    }

    rcu_read_unlock();

}



void virtio_queue_set_notification(VirtQueue *vq, int enable)
@@ -577,9 +576,8 @@ static int virtio_queue_split_empty(VirtQueue *vq) 
        return 0;

    }



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    empty = vring_avail_idx(vq) == vq->last_avail_idx;

    rcu_read_unlock();

    return empty;

}
@@ -601,12 +599,8 @@ static int virtio_queue_packed_empty_rcu(VirtQueue *vq) 


static int virtio_queue_packed_empty(VirtQueue *vq)

{

    bool empty;



    rcu_read_lock();

    empty = virtio_queue_packed_empty_rcu(vq);

    rcu_read_unlock();

    return empty;

    RCU_READ_LOCK_GUARD();

    return virtio_queue_packed_empty_rcu(vq);

}



int virtio_queue_empty(VirtQueue *vq)
@@ -859,10 +853,9 @@ void virtqueue_flush(VirtQueue *vq, unsigned int count) 
void virtqueue_push(VirtQueue *vq, const VirtQueueElement *elem,

                    unsigned int len)

{

    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    virtqueue_fill(vq, elem, len, 0);

    virtqueue_flush(vq, 1);

    rcu_read_unlock();

}



/* Called within rcu_read_lock().  */
@@ -943,7 +936,8 @@ static void virtqueue_split_get_avail_bytes(VirtQueue *vq, 
    int64_t len = 0;

    int rc;



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();



    idx = vq->last_avail_idx;

    total_bufs = in_total = out_total = 0;
@@ -1033,7 +1027,6 @@ done: 
    if (out_bytes) {

        *out_bytes = out_total;

    }

    rcu_read_unlock();

    return;



err:
@@ -1083,7 +1076,7 @@ static void virtqueue_packed_get_avail_bytes(VirtQueue *vq, 
    VRingPackedDesc desc;

    bool wrap_counter;



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    idx = vq->last_avail_idx;

    wrap_counter = vq->last_avail_wrap_counter;

    total_bufs = in_total = out_total = 0;
@@ -1176,7 +1169,6 @@ done: 
    if (out_bytes) {

        *out_bytes = out_total;

    }

    rcu_read_unlock();

    return;



err:
@@ -1360,7 +1352,7 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 
    VRingDesc desc;

    int rc;



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    if (virtio_queue_empty_rcu(vq)) {

        goto done;

    }
@@ -1469,7 +1461,6 @@ static void *virtqueue_split_pop(VirtQueue *vq, size_t sz) 
    trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);

done:

    address_space_cache_destroy(&indirect_desc_cache);

    rcu_read_unlock();



    return elem;
@@ -1494,7 +1485,7 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 
    uint16_t id;

    int rc;



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    if (virtio_queue_packed_empty_rcu(vq)) {

        goto done;

    }
@@ -1600,7 +1591,6 @@ static void *virtqueue_packed_pop(VirtQueue *vq, size_t sz) 
    trace_virtqueue_pop(vq, elem, elem->in_num, elem->out_num);

done:

    address_space_cache_destroy(&indirect_desc_cache);

    rcu_read_unlock();



    return elem;
@@ -2437,14 +2427,11 @@ static bool virtio_should_notify(VirtIODevice *vdev, VirtQueue *vq) 


void virtio_notify_irqfd(VirtIODevice *vdev, VirtQueue *vq)

{

    bool should_notify;

    rcu_read_lock();

    should_notify = virtio_should_notify(vdev, vq);

    rcu_read_unlock();



    if (!should_notify) {

    WITH_RCU_READ_LOCK_GUARD() {

        if (!virtio_should_notify(vdev, vq)) {

            return;

        }

    }



    trace_virtio_notify_irqfd(vdev, vq);
@@ -2475,14 +2462,11 @@ static void virtio_irq(VirtQueue *vq) 


void virtio_notify(VirtIODevice *vdev, VirtQueue *vq)

{

    bool should_notify;

    rcu_read_lock();

    should_notify = virtio_should_notify(vdev, vq);

    rcu_read_unlock();



    if (!should_notify) {

    WITH_RCU_READ_LOCK_GUARD() {

        if (!virtio_should_notify(vdev, vq)) {

            return;

        }

    }



    trace_virtio_notify(vdev, vq);

    virtio_irq(vq);
@@ -3032,7 +3016,7 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 
        vdev->start_on_kick = true;

    }



    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    for (i = 0; i < num; i++) {

        if (vdev->vq[i].vring.desc) {

            uint16_t nheads;
@@ -3087,7 +3071,6 @@ int virtio_load(VirtIODevice *vdev, QEMUFile *f, int version_id) 
            }

        }

    }

    rcu_read_unlock();



    if (vdc->post_load) {

        ret = vdc->post_load(vdev);
@@ -3297,12 +3280,11 @@ static void virtio_queue_packed_restore_last_avail_idx(VirtIODevice *vdev, 
static void virtio_queue_split_restore_last_avail_idx(VirtIODevice *vdev,

                                                      int n)

{

    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    if (vdev->vq[n].vring.desc) {

        vdev->vq[n].last_avail_idx = vring_used_idx(&vdev->vq[n]);

        vdev->vq[n].shadow_avail_idx = vdev->vq[n].last_avail_idx;

    }

    rcu_read_unlock();

}



void virtio_queue_restore_last_avail_idx(VirtIODevice *vdev, int n)
@@ -3322,11 +3304,10 @@ static void virtio_queue_packed_update_used_idx(VirtIODevice *vdev, int n) 


static void virtio_split_packed_update_used_idx(VirtIODevice *vdev, int n)

{

    rcu_read_lock();

    RCU_READ_LOCK_GUARD();

    if (vdev->vq[n].vring.desc) {

        vdev->vq[n].used_idx = vring_used_idx(&vdev->vq[n]);

    }

    rcu_read_unlock();

}



void virtio_queue_update_used_idx(VirtIODevice *vdev, int n)